This invention is concerned with the devices for viewing, scanning and reading information printed in the form of invisible patterns such as two-dimensional and one-dimensional bar codes. The need for this kind of devices has emerged and growing in connection with proliferation of illegally made products and documents. One of the potent ways to counter spread of counterfeit products and forged documents is to authenticate and trace migration of articles by the use of bar codes invisible to an unaided eye. Such invisible bar codes are often printed with the inks containing low concentration of colorless chemical compound fluorescing in the near infrared spectrum. In order to authenticate an article or find out the content of the covert bar code in a warehouse or in a field a portable wireless device is needed that is capable to detect the invisible bar code then acquire its image and decode its content. There are many different hand held bar code readers available for reading visible one-dimensional and two-dimensional bar codes. Reading of a bar code requires simply aiming of the scanner at the bar code pattern. All these readers belong to one of the two general categories: moving beam scanners and scanners based on imaging devices. The moving beam scanners emit a mechanically oscillating laser beam, usually of red color. User points the visible scanning pattern to overlap or cross the visible bar code. An imaging scanner needs the target space be illuminated either with ambient light or an auxiliary on-board light source. Such light source may be visible or near IR. Neither the IR illuminating beam nor ambient light assist in aiming of the scanner at the targeted bar code. Such scanners are always equipped with targeting beams that create bright visible fiducial marks on the targets. The equipment designers add such beams specifically to facilitate aiming of their scanners at the target. When the target bar code pattern is invisible the operator often does not know exact location of the bar code and would have a disturbing task of finding a bar code and precise aiming of the scanner at the invisible indicia. Even the targeting beams that create visible fiducial marks would not help much. The other problem of successfully reading the invisible bar codes is that the invisible fluorescing indicia often emit a very weak signal due to low concentration of invisible ink. The low concentration of ink helps to make the bar code pattern as difficult to detect as possible without proper equipment. A print contrast may weaken due to age or become degraded from exposure to UV light, oxygen and other elements. An invisible bar code may be printed on an uneven surface. In all such cases quality of the invisible fluorescing image produced by the image sensor depends on a relative position of the excitation beam of the scanner and orientation of its receiving beam accepting the fluorescing image. The proposed invention provides solutions to all these challenges.